So thought Denys Jeremy Douglas after the BNZ accidentally credited him with $170,000. In less than a month, he had withdrawn it all and spent it on Holdens.

Douglas, 61, a Hastings sickness beneficiary, lived a modest life on his $364 weekly benefit until June 2011, when he applied to BNZ to top up his mortgage. The bank agreed to lend him $7000 for home maintenance, a summary of facts states.

That would have taken his total mortgage to $172,250. But instead, the bank mistakenly credited that total to his account.

Douglas initially withdrew the $7000 he was entitled to. Days later, he withdrew $62,000 from his mortgage account and obtained a bank cheque for $51,000, with which he bought a 2006 Holden Clubsport R8 from a Napier car yard. He later changed the ownership into someone else's name.

The next day, he withdrew $30,000 in cash from the BNZ's Havelock North branch, $800 from its cash machine, and transferred $14,948 to Oxford Finance Corporation.

He used this to buy a 2002 Holden Commodore SS ute at a Hastings car yard, which he registered in the name of a friend, Barry Bell. He later traded in the Commodore for another Clubsport, again registered to Mr Bell.

Douglas then took his daughter to a third car yard and paid cash for a 2002 Holden Commodore VX, which he registered in her name. Again he traded the car, and used the proceeds to buy a 2007 Holden ute.

In all, he spent $171,546 in less than a month. It wasn't until his mortgage repayments went into arrears that the bank noticed its mistake.

Douglas told the bank he won some money in a lottery and had been expecting a Work and Income payment around the time that the large amount from the bank was credited to his account. He claimed it was "normal" for him to make $50,000 withdrawals, according to the summary of facts.

He pleaded guilty to seven charges of using a document and three charges of money-laundering when he appeared in the Napier District Court yesterday.

He was remanded on bail until later this month, when he will be sentenced on the 10 charges, as well as a charge of assault with a weapon.

Police recovered three vehicles, with a combined value of $121,980. The BNZ is taking legal steps to recover money owed to it, including seeking an order to "repatriate" the Clubsport that was bought with a bank cheque.

The bank said Douglas had "used funds that were incorrectly allocated to his account due to a keying error". It went through its usual processes to recover the money, and forwarded the matter to police for criminal investigation.